It is known to drop cup-shaped cuvettes from a source, e.g., a stack, onto a conveyor of some kind, as shown in, e.g., U.S. Pat. Nos. 5,271,896 (FIGS. 4-8) and 5,244,633. However, it is important when this is done that only one cuvette be dispensed at a time. Prior to this invention, there has been a need for apparatus which advises specifically that there is more than one cuvette sitting at one station in the conveyor.